One of the first decisions when choosing a standby generator is the fuel source. In the Aiken area, you have two practical options: propane (liquid propane gas, or LP) and natural gas. Both fuels work well, but they have meaningful differences in availability, cost, convenience, and performance that depend heavily on where you live in Aiken County. This guide breaks down the comparison so you can make an informed decision for your specific situation.
Fuel Availability in the Aiken Area
The most important factor in the propane versus natural gas decision is simple: what is available at your property? In many parts of Aiken County, this factor alone makes the decision for you.
Natural Gas Availability
Natural gas service in the Aiken area is provided by Dominion Energy (formerly SCANA). However, natural gas infrastructure does not extend to all areas. Natural gas is generally available in the city of Aiken proper, established subdivisions within or near city limits, parts of North Augusta, and some areas along major corridors.
Much of rural Aiken County has no natural gas infrastructure. If you live in Graniteville, Wagener, Salley, Windsor, Monetta, or the more rural areas between towns, natural gas is almost certainly not available at your property. Before planning a natural gas generator, verify with Dominion Energy that gas service exists at your address or can be extended to your property. Running a new gas line from the main to your home can cost thousands of dollars if the main is not nearby.
Propane Availability
Propane is available everywhere. It is delivered by truck to a tank on your property, so there is no infrastructure requirement. Several propane suppliers serve the Aiken area, including Suburban Propane, AmeriGas, Blossman Gas, and local independent dealers. Competition between suppliers keeps pricing competitive.
Propane requires a storage tank on your property. Tanks are available for purchase or lease from propane suppliers. Common sizes for generator use range from 250 gallons (suitable for short outages) to 1,000 gallons (suitable for extended outages lasting a week or more). The tank must be placed according to local setback requirements, typically at least 10 feet from the home and 10 feet from any ignition source.
Cost Comparison
Fuel Cost Per Hour of Operation
The cost to run your generator depends on the fuel price, the generator size, and the electrical load. Here is a representative comparison for a 22kW generator running at 50 percent load (typical for a home during an outage):
- Natural gas: A 22kW generator at half load consumes approximately 200 to 250 cubic feet of natural gas per hour. At typical Aiken residential rates of around $1.00 to $1.50 per therm (100 cubic feet), this translates to roughly $2.00 to $3.75 per hour of operation
- Propane: The same generator at half load consumes approximately 2 to 3 gallons of propane per hour. At typical delivered propane prices of $2.50 to $3.50 per gallon in the Aiken area, this translates to roughly $5.00 to $10.50 per hour of operation
Natural gas is clearly less expensive to operate on a per-hour basis. During a 48-hour outage, a natural gas generator might cost $100 to $180 in fuel, while a propane generator could cost $240 to $500 for the same period. Over the life of the generator, this difference can add up to thousands of dollars if you experience frequent or extended outages.
Equipment Cost
The generator itself costs roughly the same regardless of fuel type. Most standby generators are available in both natural gas and propane configurations, or they come as dual-fuel units that can run on either fuel with a simple conversion. The price difference between fuel configurations is typically less than $200.
Installation Cost Differences
Installation costs differ more significantly:
- Natural gas installation: Requires running a gas line from your existing gas meter to the generator location. The gas meter may need to be upgraded to handle the additional load. Typical cost for gas line routing: $500 to $2,000 depending on distance and complexity. Meter upgrade if needed: $200 to $500
- Propane installation: Requires a propane tank (purchase $800 to $2,500 or lease $50 to $150 per year) plus a gas line from the tank to the generator ($500 to $1,500). Total upfront cost for propane infrastructure: $1,300 to $4,000
If you already have natural gas service to your home, the installation cost for a natural gas generator is typically lower because you are tapping into existing infrastructure. If you need new propane infrastructure, the upfront cost is higher but the ongoing tank lease or ownership cost is relatively modest.
Reliability During Emergencies
Natural Gas Reliability
Natural gas is delivered through underground pipelines, which are highly reliable during most weather events. Underground gas lines are not affected by wind, falling trees, or ice that commonly damage above-ground power lines. However, natural gas has one significant vulnerability: during major regional emergencies, gas pressure in the distribution system can drop if demand spikes across the entire service area.
This scenario is uncommon in the Aiken area, but it has occurred in other regions during extreme cold events when heating demand spiked simultaneously across millions of homes. If gas pressure drops below the generator's minimum operating pressure, the generator will shut down. You have no stored fuel reserve to fall back on.
The practical risk is low for Aiken. The climate is mild enough that extreme gas demand events are rare, and the natural gas infrastructure in the area is generally well-maintained. But it is a factor worth considering, especially if you are in an area with older gas infrastructure.
Propane Reliability
Propane's reliability advantage is fuel independence. Your propane is stored on your property in your tank. No pipeline, no utility company, no shared infrastructure. If you have fuel in the tank, you have power. Period.
The vulnerability with propane is that your fuel supply is finite. A 500-gallon tank powering a 22kW generator at half load will last approximately 5 to 7 days of continuous operation. If the outage lasts longer, you need a propane delivery. During widespread emergencies, propane suppliers can be overwhelmed with delivery requests, and road conditions may prevent trucks from reaching your property.
The mitigation strategy is simple: install a larger tank and keep it full. A 1,000-gallon tank gives you 10 to 14 days of runtime, which covers virtually any outage scenario in the Aiken area. Top off the tank before storm season each year.
Performance Differences
Power Output
Propane produces slightly more power per unit of fuel than natural gas. A generator rated at 22kW on propane may be rated at only 20kW on natural gas, roughly a 10 percent reduction. This is because propane has a higher energy density (BTUs per cubic foot) than natural gas. Most manufacturers publish separate ratings for each fuel type.
This difference means that if you are sizing a generator for whole-home coverage and need every kilowatt, a natural gas unit may need to be one size larger than a propane unit to deliver the same power. This can affect equipment cost.
Cold Weather Performance
Propane vaporizes at minus 44 degrees Fahrenheit, so it remains gaseous and flows reliably at any temperature Aiken will ever experience. Natural gas is always delivered in gaseous form through the pipeline, so cold weather does not affect its delivery. Both fuels perform well in Aiken's relatively mild winters.
However, propane tanks must be large enough to sustain adequate vaporization rates. In very cold weather (rare in Aiken but possible), a nearly empty propane tank may not vaporize propane fast enough to feed the generator at full load. Keeping the tank at least 25 percent full prevents this issue.
Engine Life and Maintenance
Natural gas burns slightly cleaner than propane, producing less carbon buildup in the engine. This can translate to slightly longer intervals between spark plug replacements and marginally less engine wear over decades of operation. In practice, the difference is modest, and both fuels result in significantly less engine wear than gasoline or diesel.
Dual-Fuel and Conversion Options
Many standby generators are available as dual-fuel units that can run on either propane or natural gas. Dual-fuel generators include the plumbing connections and fuel regulation equipment for both fuels. Switching between fuels requires a technician to adjust the fuel system, but it is not a complex or expensive process.
Dual-fuel capability is particularly useful if you currently have propane but anticipate natural gas becoming available in your area in the future. You can install the generator on propane today and convert to natural gas later without replacing the generator.
If your generator is not dual-fuel, conversion kits are available for most models. A propane-to-natural-gas conversion typically costs $300 to $600 for parts and labor. Going the other direction (natural gas to propane) costs a similar amount. Not all generators support conversion, so check with the manufacturer before planning a fuel switch.
Making the Right Choice for Your Aiken Home
Choose Natural Gas If:
- You already have natural gas service at your home
- You want the lowest operating cost per hour
- You want unlimited runtime without worrying about fuel delivery
- You prefer not to have a propane tank on your property
- You live within Aiken city limits or an area with reliable gas service
Choose Propane If:
- Natural gas is not available at your property
- You want complete fuel independence from utility infrastructure
- You live in a rural area where propane is the standard fuel
- You already have a propane tank for home heating or cooking
- You want slightly higher power output from the same generator size
For many homeowners in rural Aiken County, propane is the only practical option, and it is an excellent one. For homeowners within Aiken city limits with existing natural gas service, natural gas offers lower operating costs and the convenience of an unlimited fuel supply.
Unity Power & Light installs standby generators on both propane and natural gas throughout Aiken County. We help you evaluate fuel availability at your property, compare costs for your specific situation, and select the right generator configuration. Call us at (803) 220-4491 for a free consultation and site assessment.